As you know Oxford and Cambridge are two oldest and popular universities of UK; many students dream about being here! There are some similarities and also differences between them. It is hard to answer question of Oxford or Cambridge? First of all we can say both of them are well known universities all around the world. You can not apply both of them at the same time. So; you need to choose one and stick to it. These universities are really similar at first glance; because they use same teaching methods and collegiate system, they both really famous in world. According to QS World University Rankings 2015-2016 University of Oxford is 6th university in the world and University of Cambridge is 3rd university in world. Courses can be a distinguishing property among them. Some courses are only available for one of them. That makes easier to choose one! If you want to study in science; there is big difference between them. At Cambridge you can choose different scientific courses at the same time; but in Oxford you can choose only one of them.
There are some changes in terms of location. Oxford is a city but Cambridge is like a town. Traffic can be a problem for Oxford by Cambridge is more quite place. But they both have lovely architecture and history. If you want places like many shops and bars I think Oxford will be more proper.
Cambridge focus more on science and Oxford well know with humanities subjects. Both of these universities offer scholarship for students. But I can say you need to get into a huge competition to earn a scholarship in these universities! I hope you will find the best university and be happy here.